... is a grand way of building a system with a lot of moving parts. A simple system has two main things: resources and functions. Resources - such as databases and file systems - is where all information is stored and retrieved. Functions, and the applications that execute them, are the means to interact with the resources. Applications come in a number of guises such as web sites, desktop applications and mobile applications.
Depending on the size and scale of the system; applications can directly connect to these resources. Kind of like a Tie Fighter docking directly into the Death Star. The Death Star being a central core of massive evil; like, for example, a Microsoft Access Database.
But let's say distributing this evil is a galactical ambition and having one place where you can arm, equip and feed the Storm Troopers and send them out to do your nefarious bidding becomes a bottleneck. To scale, you would have look at spreading the resources and facilities around a bit. You could, for instance, take over a planet and build additional docking stations, dormitories with foosball (for those times when the rebels are not trying to overthrow you), and an array of vehicles you could use to turn small furry natives into road kill. The planet would then become a disconnected, fully functioning service of evil.